The synthesis of glycosaminoglycans in aging rat liver. A brief note

The synthesis of glycosaminoglycans (GAG) was studied in liver slices from postnatal (9 days), young (140 days), adult (490 days) and senescent (940 days) rats. It was found that the rate of synthesis was highest in postnatal rat liver and decreased to about half in young rats with no further reduction in adult and senescent age groups. The specific radioactivity of the precursors of GAG synthesis did not change with age. The synthesis pattern of specific types of GAG in postnatal liver was characterized by a significant higher percentage of chondroitin sulfate and hyaluronic acid. In the following age classes the profile of specific GAG synthesis did not change significantly (heparin sulfate: chondroitin sulfate" hyaluronic acid: "keratin sulfate" = 84%:8.3%:1.5%:1.6%).